401/405 Error Symfony 4 REST: JWT API Authentication (LexikJWTAuthenticationBundle) on docker - ngnix

I wanted to integrate a authentification login into the backend of my REST Api.

I installed and configured the LexikJWTAuthenticationBundle in my REST-API backend following this tutorial: https://www.youtube.com/watch?v=XT4oy1d1j-g

The backend is running in the ngnix docker container.

But when I try to generate a token with

curl -X POST -H "Content-Type: application/json" docker-backend.test/api/login_check -d '{"username":"admin@admin.com","password":"1111"}'

I get:

{"code":500,"message":"Unable to create a signed JWT from the given configuration."}

The database Entry of the user is created via Fixtures:

$user = new User();
$user->setEmail('admin@admin.com');
$user->setRoles(['ROLE_USER']);
$user->setPassword(
   //encode the password
   $this->encoder->encodePassword($user, '1111')
);
$manager->persist($user);
$manager->flush();

The db entry of the Password is:

$argon2i$v=19$m=1024,t=2,p=2$b2hSY2pVYkc0Ym53V09Ucg$LBfYYmXE9/9h3VKkcdxHXwHNOIMgw/G6W89H7SU58Ns

My docker-compose.yaml:

version: "3.1"
services:

    mysql:
      image: mysql:5.7
#5.7 weil 8.0 eine unbekannte authentifizierungsmethode bei symfony4 hat
      container_name: docker-symfony4-mysql
      working_dir: /backend
      volumes:
        - ./backend:/backend
      environment:
        - MYSQL_ROOT_PASSWORD=secret
        - MYSQL_DATABASE=rest-backend
        - MYSQL_USER=homestead
        - MYSQL_PASSWORD=secret
      ports:
        - "127.0.3.3:8002:3306"

    backend-server:
      image: nginx:alpine
      container_name: docker-rest-backend-server
      working_dir: /backend
      volumes:
          - ./backend:/backend
          - ./phpdocker/nginx/nginx.conf:/etc/nginx/conf.d/default.conf
      ports:
       - "127.0.3.2:80:80"
      depends_on:
       - mysql

    php-fpm:
      build: phpdocker/php-fpm
      container_name: docker-rest-php-fpm
      working_dir: /backend
      volumes:
        - ./backend:/backend
        - ./phpdocker/php-fpm/php-ini-overrides.ini:/etc/php/7.2/fpm/conf.d/99-overrides.ini
      depends_on:
       - mysql

    frontend-server:
      image: nginx:alpine
      container_name: docker-rest-frontend-server
      working_dir: /frontend
      volumes:
          - ./frontend:/frontend
          - ./phpdocker/nginx-frontend/nginx.conf:/etc/nginx/conf.d/default.conf
      ports:
       - "127.0.3.1:80:80"
      depends_on:
       - mysql

security.yaml

security:
    encoders:
        App\Entity\User:
            algorithm: argon2i
    providers:
        app_user_provider:
            entity:
                class: App\Entity\User
                property: email
    firewalls:
        dev:
            pattern: ^/(_(profiler|wdt)|css|images|js)/
            security: false
        login:
            pattern:  ^/api/login
            stateless: true
            anonymous: true
            json_login:
                check_path: /api/login_check
                success_handler: lexik_jwt_authentication.handler.authentication_success
                failure_handler: lexik_jwt_authentication.handler.authentication_failure
        api:
            pattern:   ^/api
            stateless: true
            guard:
                authenticators:
                - lexik_jwt_authentication.jwt_token_authenticator
        main:
            anonymous: true
    access_control:
    - { path: ^/api/login, roles: IS_AUTHENTICATED_ANONYMOUSLY }
    - { path: ^/api,       roles: IS_AUTHENTICATED_FULLY }

lexik_jwt_authentication.yaml

lexik_jwt_authentication:
    secret_key: '%kernel.project_dir%/config/jwt/private.pem' 
    public_key: '%kernel.project_dir%/config/jwt/public.pem' 
    pass_phrase: '%env(JWT_PASSPHRASE)%' 
    token_ttl: 3600

routes.yaml

api_login_check:
  path: /api/login_check

.env

[...]
JWT_SECRET_KEY=%kernel.project_dir%/config/jwt/private.pem
JWT_PUBLIC_KEY=%kernel.project_dir%/config/jwt/public.pem
JWT_PASSPHRASE=8e5433ff410b05fe7dbb26ef6cdf9bae

If you need to look at other code, which isn't posted here, have a look at my Repo: https://github.com/beerfekt/REST-API-Backend-Docker

I tried a lot of solutions and searched a lot of sites, but nothing worked.

I solved it with the solution given in https://github.com/lexik/LexikJWTAuthenticationBundle/issues/532 :

My Passphrase in the .env file was not the same like the phrase of the generated keys in (Verifying - Enter pass phrase for config/jwt/private.pem:).

Now the Token is generated successfully.